1. Field of the Invention
This invention relates to amusement devices used for entertainment and decoration that have a fluid filled transparent enclosure in which decorative particles can be suspended by fluid agitation and typically display a figurine within the enclosure.
2. Description of Related Art
At their most fundamental level these amusement devices (often termed snow globes, or water globes, among other variations), require manual shaking to disperse the decorative particles inside the fluid filled enclosure. However, the decorative particles settle to the bottom of the enclosure and the ornamental value of the device is soon lost. Almost constant manual agitation is required to maintain the ornamental effect of the particles swirling around the figurine. Consequently, the snow globe is usually displayed without particle movement, in a lack luster state. This does not set off the globe to its most aesthetic and interesting advantage.
Considerable inventive activity has been directed at the development of mechanical or electrical powered systems that aromatically disperse the decorative particles in these amusement devices. These improved devices have used mechanical and electrical motors to drive small pumps that agitate the enclosure fluid to disperse the decorative particles.
These patents include Murray (U.S. Pat. No. 5,313,727), Ingram (U.S. Pat. No. 5,491,916), Powell (U.S. Pat. No. 5,502,908), and Ong (U.S. Pat. No. 4,817,311).
The resultant continuous particle movement created by these improved devices creates a pleasing visual effect for both amusement and decoration without the need for manual agitation. Viewers enjoy a continuous visual display without resorting to what would otherwise require almost continuous manual agitation of the globe. The snow globe can always be presented in its most visually interesting and pleasing aesthetic state without the bother of manually agitating the device.
All of the above referenced patents, however, suffer from the same basic design flaw. All of these devices utilize a mechanical shaft to transmit power from the driver (e.g., electric motor or mechanical spring) to the pump. Because the shaft must protrude into the fluid filled snow globe to power the pump, all of the above patented devices suffer from the same problem, shaft leakage. Although the shaft is sealed with some sort of mechanical seal to prevent leakage, no mechanical seal can perfectly seal a fluid. Some leakage is always present because of the seepage that any seal will experience. Furthermore, this seal is eventually guaranteed to fail and leak catastrophically. These leaks occur because the seal wears, or the seal material degrades, or the seal becomes misaligned.
Because of the ornamental nature of snow globes, they are often displayed on wood furniture such as tables and cabinetry. In these vulnerable areas there is no allowable tolerance for leakage because of the water damage that will occur. Even the slight seepage that can be expected is too much moisture in these areas. None of the patents disclosed above has resolved this leakage problem.
This invention relates to a new and useful improvement in snow globes for the continuous circulation and dispersion of particles inside the globe. The greatest advantage of this invention is that a simple, economical method has been developed to provide a reliable leak proof seal. This invention improves upon the prior art with the application of a magnetic coupling of the drive mechanism to the pump.
The magnetic coupling allows the pump and all of the pump""s components to be hermetically sealed from the drive mechanism. All other systems require a seal to accommodate a rotating shaft connecting the motor to the impeller. Such a seal will wear and eventually leak. In contrast, this invention does not require a seal because the fluid boundary is never breached. Leakage is impossible because there is no mechanical shaft penetrating the fluid boundary.
Another advantage of this invention over the prior art is that fewer and simpler components are required to make this invention operable. For example, the present invention requires neither a mechanical seal nor a drive shaft. Furthermore, none of the ancillary components required to couple the shaft to the drive and the impeller are required. As a result the assembly cost for the present invention is also reduced.
This invention dramatically changes the manner of use and display of traditional snow globes and similar amusement devices. In the past a snow globe required manual agitation to affect the desired display of falling snow (or other decorative particles). This new invention provides a constant display of circulating particles without the nuisance of providing constant manual agitation and without the fear that their globe will leak. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.